Re: scsi: aic7xxx hang since v2.6.28-rc1 ...

[Mike Anderson <andmike@linux.vnet.ibm.com>]

Ingo Molnar <mingo@elte.hu> wrote:
> 
> * Alan Stern <stern@rowland.harvard.edu> wrote:
> 
> > I have no idea if this will make any difference for the 
> > problem you're seeing, but it has been submitted and it's 
> > worth trying out.  If the problem still occurs, I'll write a 
> > diagnostic patch to add log messages giving the destiny of 
> > each request in scsi_io_completion().
> 
> OK, i've undone the reverts and have applied your fix - it will 
> take a few hours to see whether the hang still occurs.
> 

I know already started your testing, but..

I find it informative to set my scsi logging to the value below to display
non-zero IO status on commands. The overhead impact is low for good
completions.

sysctl -w dev.scsi.logging_level=4100

Note: This does not provide the exact policy that scsi_io_completion will
take on the IO, but it provides the input to scsi_io_completion which
should help.

-andmike
--
Michael Anderson
andmike@linux.vnet.ibm.com